CN113329513B

CN113329513B - Method and apparatus for wireless communication over a shared medium

Info

Publication number: CN113329513B
Application number: CN202110748530.4A
Authority: CN
Inventors: S·莫林
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2017-09-15
Filing date: 2018-09-15
Publication date: 2024-04-30
Anticipated expiration: 2038-09-15
Also published as: US20220417945A1; US20210014871A1; WO2019055881A1; CN111095840B; CN111095840A; US10728912B2; US20190090255A1; CN113329513A; US11438911B2

Abstract

In an aspect of the disclosure, a method, computer-readable medium, and apparatus are provided, in particular, a method and apparatus for wireless communication over a shared medium. The equipment obtains a signal from a remote wireless node. The equipment may switch between the first mode and the second mode in response to the signal. The equipment may sense the shared transmission medium and sense whether a loss of traffic is detected. The equipment may delay data transmission for a fixed time interval from detection of the lack of traffic. The apparatus may initiate a data transmission at the end of the fixed time interval if operating in the first mode; or may initiate a data transmission at the end of a random time interval following a fixed time interval if operating in the second mode.

Description

Method and apparatus for wireless communication over a shared medium

The application is a divisional application of Chinese patent application with the application number 201880059278.2 of 2018, 9, 15 and the application name of 'method and device for wireless communication on shared medium'.

Cross-reference to related application(s)

The present application claims the benefit of U.S. provisional application S/n.62/559,478 entitled "SYNCHRONIZED MEDIUM REUSE SEQUENCE (synchronized media reuse sequence)" filed on day 15 of 2017, and U.S. patent application No.16/132,258 entitled "SYSTEM AND METHOD OF MODES FOR DATA TRANSMISSION (system and method for data transfer mode)" filed on day 14 of 2018, both of which are expressly incorporated herein by reference in their entirety.

Background

FIELD

The present disclosure relates generally to communication systems, and more particularly to transmitting data according to different modes.

Background

A communication network is used to exchange messages between several interacting devices that are spatially separated. The network may be classified according to geographic scope, which may be, for example, a metropolitan area, a local area, or a personal area. Such networks will be designated as Wide Area Networks (WANs), metropolitan Area Networks (MANs), local Area Networks (LANs), wireless Local Area Networks (WLANs), or Personal Area Networks (PANs), respectively. Networks also vary according to the switching/routing techniques (e.g., circuit switched versus packet switched), the type of physical medium used for transmission (e.g., wire versus wireless), and the communication protocol sets used (e.g., internet protocol suite, synchronous Optical Networking (SONET), ethernet, etc.) used to interconnect the various network nodes and devices.

Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and so on. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include Code Division Multiple Access (CDMA) networks, time Division Multiple Access (TDMA) networks, frequency Division Multiple Access (FDMA) networks, orthogonal FDMA (OFDMA) networks, and single carrier FDMA (SC-FDMA) networks.

SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

The following disclosure describes within scope methods, techniques, and protocols for synchronizing transmissions (e.g., from an access point). Such transmissions may be well synchronized (e.g., within 1.5 mus when the fixed interval is PIFS) to allow the receiver to lock into the desired packet and achieve a lower Packet Error Rate (PER).

In an aspect of the disclosure, a method, computer-readable medium, and apparatus are provided. The apparatus may include a first interface configured to obtain a signal from a wireless node; and a processing system configured to: selecting to operate in either the first mode or the second mode in response to the signal; detecting a traffic loss on the shared medium during a fixed time interval; and initiating a data transmission at the end of the fixed time interval if operating in the first mode or at the end of a random time interval following the fixed time interval if operating in the second mode. In an aspect, the processing system is further configured to initiate data transmission in the first mode by generating a plurality of data frames separated by a fixed time interval, and the apparatus further comprises: a second interface configured to output a plurality of data frames for transmission. In an aspect, the processing system is further configured to terminate the data transmission if a time period associated with the data transmission exceeds a maximum time interval, the time period following initiation of the data transmission. In an aspect, the processing system is further configured to: generating a block acknowledgement request, and scheduling transmission of the block acknowledgement request after a maximum time interval; and the apparatus further comprises a second interface configured to output a block acknowledgement request for the scheduled transmission. In an aspect, the processing system is further configured to initiate transmission of the block acknowledgement if another traffic loss is detected on the shared medium after the end of the data transmission. In an aspect, the processing system is further configured to monitor the shared medium to determine one or more parameters and provide the one or more parameters to the remote wireless node. In an aspect, the one or more parameters include at least one of a received signal strength from a wireless node in communication with the equipment or a detected interference associated with the shared medium.

In an aspect, an apparatus may include means for acquiring a signal from a wireless node. The apparatus may include means for selecting operation in the first mode or the second mode in response to the signal. An apparatus may include means for detecting a lack of traffic on a shared medium during a fixed time interval. The apparatus may include means for initiating a data transmission at the end of a fixed time interval if operating in the first mode or at the end of a random time interval following the fixed time interval if operating in the second mode. In an aspect, an apparatus for initiating data transmission is configured to generate a plurality of data frames separated by a fixed time interval and output the plurality of data frames for transmission. In an aspect, an apparatus may include means for terminating a data transmission if a time period associated with the data transmission exceeds a maximum time interval, the time period following initiation of the data transmission. In an aspect, an apparatus may include means for generating a block acknowledgement request; means for scheduling transmission of the block acknowledgement request after a maximum time interval; and means for outputting a block acknowledgement request for the scheduled transmission. In an aspect, an apparatus may include means for initiating transmission of a block acknowledgement if another traffic loss is detected on a shared medium after an end of a data transmission. In an aspect, an apparatus may include means for monitoring a shared medium to determine one or more parameters and providing the one or more parameters to a remote wireless node. In an aspect, the one or more parameters include at least one of a received signal strength from a wireless node in communication with the equipment or a detected interference associated with the shared medium.

The method may include obtaining a signal from a wireless node; selecting to operate in either the first mode or the second mode in response to the signal; detecting a traffic loss on the shared medium during a fixed time interval; and initiating a data transmission at the end of the fixed time interval if operating in the first mode or at the end of a random time interval following the fixed time interval if operating in the second mode. In an aspect, initiating data transmission in a first mode includes: generating a plurality of data frames separated by a fixed time interval; and outputting the plurality of data frames for transmission. The method may further include terminating the data transmission if a time period associated with the data transmission exceeds a maximum time interval, the time period following initiation of the data transmission. The method may further include generating a block acknowledgement request; scheduling transmission of the block acknowledgement request after a maximum time interval; and outputting a block acknowledgement request for the scheduled transmission. The method may further include initiating transmission of a block acknowledgement if another traffic loss is detected on the shared medium after the end of the data transmission. The method may further include monitoring the shared medium to determine one or more parameters and providing the one or more parameters to the remote wireless node. In an aspect, the one or more parameters include at least one of a received signal strength from a wireless node in communication with the equipment or a detected interference associated with the shared medium.

A computer-readable medium, the computer-readable medium comprising code for wireless communication, the code executable to cause an apparatus to: obtaining a signal from a wireless node; selecting to operate in either the first mode or the second mode in response to the signal; detecting a traffic loss on the shared medium during a fixed time interval; and initiating a data transmission at the end of the fixed time interval if operating in the first mode or at the end of a random time interval following the fixed time interval if operating in the second mode.

A wireless node for wireless communication over a shared transmission medium may be provided. The wireless node includes a receiver configured to receive a signal from the wireless node; and a processing system configured to: selecting to operate in either the first mode or the second mode in response to the signal; detecting a traffic loss on the shared medium during a fixed time interval; and initiating a data transmission at the end of the fixed time interval if operating in the first mode or at the end of a random time interval following the fixed time interval if operating in the second mode.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed and the present description is intended to include all such aspects and their equivalents.

Brief Description of Drawings

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects.

Fig. 1 illustrates a diagram of an example wireless communication network, in accordance with certain aspects of the present disclosure.

Fig. 2 illustrates a block diagram of an example Access Point (AP) and User Terminal (UT) in accordance with certain aspects of the disclosure.

Fig. 3 illustrates an exemplary method for communicating over a medium.

Fig. 4A and 4B illustrate diagrams of an AP operating in a first mode and a second mode.

Fig. 5A and 5B illustrate diagrams relating to sequence robustness.

Fig. 6A and 6B illustrate diagrams of acknowledging transmissions in a synchronization sequence.

Fig. 7 is a diagram illustrating an exemplary method for communicating over a medium.

Fig. 8 illustrates an example functional block diagram of a wireless device configured to communicate over a medium.

Fig. 9 is a flow chart of a method for communicating over a medium.

Fig. 10 is a block diagram illustrating an exemplary device.

Detailed Description

Various aspects of the disclosure are described more fully below with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein one skilled in the art will appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method of practice may be practiced using any number of the aspects set forth herein. In addition, the scope of the present disclosure is intended to cover such an apparatus or method that is practiced using such structure, functionality, or both as a complement to, or in addition to, the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the claims.

The term "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects.

Although specific aspects are described herein, numerous variations and permutations of these aspects fall within the scope of the disclosure. Although some benefits and advantages of the preferred aspects are mentioned, the scope of the present disclosure is not intended to be limited to a particular benefit, use, or goal. Rather, aspects of the present disclosure are intended to be broadly applicable to different wireless technologies, system configurations, networks, and transmission protocols, some of which are illustrated by way of example in the figures and the following description of preferred aspects. The detailed description and drawings are merely illustrative of the present disclosure rather than limiting, the scope of the present disclosure being defined by the appended claims and equivalents thereof.

Example Wireless communication System

The techniques described herein may be used for various broadband wireless communication systems including communication systems based on orthogonal multiplexing schemes. Examples of such communication systems include Spatial Division Multiple Access (SDMA), time Division Multiple Access (TDMA), orthogonal Frequency Division Multiple Access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and the like. SDMA systems may utilize substantially different directions to simultaneously transmit data belonging to multiple user terminals. TDMA systems may allow multiple user terminals to share the same frequency channel by dividing the transmission signal in different time slots, each time slot being assigned to a different user terminal. OFDMA systems utilize Orthogonal Frequency Division Multiplexing (OFDM), a modulation technique that divides the overall system bandwidth into multiple orthogonal subcarriers. These subcarriers may also be referred to as tones, bins, etc. Under OFDM, each subcarrier can be modulated independently with data. SC-FDMA systems may utilize Interleaved FDMA (IFDMA) to transmit on subcarriers distributed across the system bandwidth, localized FDMA (LFDMA) to transmit on blocks of contiguous subcarriers, or Enhanced FDMA (EFDMA) to transmit on multiple blocks of contiguous subcarriers. In general, modulation symbols are transmitted in the frequency domain under OFDM and in the time domain under SC-FDMA.

The teachings herein may be incorporated into (e.g., implemented within or performed by) a wide variety of wired or wireless equipment (e.g., nodes). In some aspects, a wireless node implemented according to the teachings herein may comprise an access point or an access terminal.

An access point ("AP") may include, be implemented as, or be referred to as a node B, a radio network controller ("RNC"), an evolved node B (eNB), a base station controller ("BSC"), a base transceiver station ("BTS"), a base station ("BS"), a transceiver function ("TF"), a radio router, a radio transceiver, a basic service set ("BSs"), an extended service set ("ESS"), a radio base station ("RBS"), or some other terminology.

An access terminal ("AT") may include, be implemented as, or be referred to as a subscriber station, a subscriber unit, a Mobile Station (MS), a remote station, a remote terminal, a User Terminal (UT), a user agent, a User Equipment (UE), a subscriber station, or some other terminology. In some implementations, an access terminal may comprise a cellular telephone, a cordless telephone, a session initiation protocol ("SIP") phone, a wireless local loop ("WLL") station, a personal digital assistant ("PDA"), a handheld device having wireless connection capability, a station ("STA"), or some other suitable processing device connected to a wireless modem. Accordingly, one or more aspects taught herein may be incorporated into a phone (e.g., a cellular phone or a smart phone), a computer (e.g., a laptop), a tablet device, a portable communication device, a portable computing device (e.g., a personal data assistant), an entertainment device (e.g., a music or video device, or a satellite radio), a Global Positioning System (GPS) device, or any other suitable device that is configured to communicate via a wireless or wired medium. In some aspects, the node is a wireless node. Such wireless nodes may provide connectivity to or to a network (e.g., a wide area network such as the internet) or a cellular network), for example, via wired or wireless communication links.

Fig. 1 illustrates a multiple-access multiple-input multiple-output (MIMO) system 100 with access points and user terminals in which aspects of the present disclosure may be practiced. For example, one or more user terminals 120 can employ the techniques provided herein to signal capabilities (e.g., to access point 110).

For simplicity, only one access point 110 is shown in fig. 1. An access point is typically a fixed station that communicates with the user terminals and may also be referred to as a base station or some other terminology. A user terminal may be fixed or mobile and may also be referred to as a mobile station, a wireless node, or some other terminology. Access point 110 may communicate with one or more user terminals 120 on the downlink and uplink at any given moment. The downlink (i.e., forward link) is the communication link from the access point to the user terminal, and the uplink (i.e., reverse link) is the communication link from the user terminal to the access point. A user terminal may also communicate peer-to-peer with another user terminal. A system controller 130 is coupled to and provides coordination and control for the access points.

While portions of the disclosure below will describe user terminals 120 capable of communicating via Spatial Division Multiple Access (SDMA), for certain aspects, user terminals 120 may also include some user terminals that do not support SDMA. Thus, for such aspects, the AP 110 may be configured to communicate with both SDMA user terminals and non-SDMA user terminals. This approach may facilitate allowing older versions of user terminals ("legacy" stations) to remain deployed in the enterprise to extend their useful life, while allowing newer SDMA user terminals to be introduced where deemed appropriate.

The access point 110 and the user terminal 120 employ multiple transmit antennas and multiple receive antennas for data transmission on the downlink and uplink. For downlink MIMO transmissions, N _ap antennas of access point 110 represent the multiple-input (MI) portion of MIMO, and a set of K user terminals represent the multiple-output (MO) portion of MIMO. In contrast, for uplink MIMO transmission, the set of K user terminals represents the MI part, while the N _ap antennas of access point 110 represent the MO part. For pure SDMA, if the data symbol streams for K user terminals are not multiplexed in code, frequency, or time by some means, it is desirable to have N _ap. Gtoreq.K.gtoreq.1. K may be greater than N _ap if the data symbol streams can be multiplexed using TDMA techniques, using different code channels under CDMA, using disjoint sets of subbands under OFDM, and so on. Each selected user terminal transmits user-specific data to and/or receives user-specific data from the access point. In general, each selected user terminal may be equipped with one or more antennas (i.e., N _ut. Gtoreq.1). The K selected user terminals may have the same or different numbers of antennas.

System 100 may be a Time Division Duplex (TDD) system or a Frequency Division Duplex (FDD) system. For a TDD system, the downlink and uplink share the same frequency band. For FDD systems, the downlink and uplink use different frequency bands. MIMO system 100 may also utilize single carrier or multi-carrier transmission. Each user terminal may be equipped with a single antenna (e.g., to suppress costs) or multiple antennas (e.g., where additional costs can be supported). The system 100 may also be a TDMA system if the user terminals 120 share the same frequency channel by dividing transmission/reception in different time slots, each time slot being assigned to a different user terminal 120.

Fig. 2 illustrates a block diagram of an access point 110 and two user terminals 120m and 120x in a MIMO system 100, which may be examples of the access point 110 and user terminal 120 described above with reference to fig. 1 and capable of performing the techniques described herein. The various processors shown in fig. 2 may be configured to perform (or direct the device to perform) the various methods described herein.

The access point 110 is equipped with N _ap antennas 224a through 224ap. User terminal 120m is equipped with N _ut,m antennas 252ma through 252mu, while user terminal 120x is equipped with N _ut,x antennas 252xa through 252xu. The access point 110 is a transmitting entity for the downlink and a receiver entity for the uplink. Each user terminal 120 is a transmitting entity for the uplink and a receiver entity for the downlink. As used herein, a "transmitting entity" is a separately operated apparatus or device capable of transmitting data via a wireless channel, while a "receiver entity" is a separately operated apparatus or device capable of receiving data via a wireless channel. In the following description, the subscript "dn" designates downlink and the subscript "up" designates uplink. For SDMA transmissions, N _up user terminals transmit simultaneously on the uplink, while access point 110 transmits simultaneously on the downlink to N _dn user terminals. N _up may or may not be equal to N _dn, and N _up and N _dn may be static values or may vary for each scheduling interval. Beam steering or some other spatial processing technique may be used at the access point and user terminal.

On the uplink, at each user terminal 120 selected for uplink transmission, a Transmit (TX) data processor 288 receives traffic data from a data source 286 and control data from a controller 280. The controller 280 may be coupled with a memory 282. TX data processor 288 processes (e.g., encodes, interleaves, and modulates) the traffic data for the user terminal based on the coding and modulation schemes associated with the selected rate for that user terminal and provides a stream of data symbols. TX spatial processor 290 performs spatial processing on the data symbol streams and provides N _ut,m transmit symbol streams to N _ut,m antennas. Each transmitter unit (TMTR) 254 receives and processes (e.g., converts to analog, amplifies, filters, and frequency upconverts) a corresponding transmit symbol stream to generate an uplink signal. N _ut,m transmitter units 254 provide N _ut,m uplink signals for transmission from N _ut,m antennas 252 to the access point.

N _up user terminals may be scheduled for simultaneous transmission on the uplink. Each of these user terminals performs spatial processing on its data symbol stream and transmits its set of transmit symbol streams on the uplink to the access point.

At access point 110, N _ap antennas 224a through 224ap receive the uplink signals from all N _up user terminals transmitting on the uplink. Each antenna 224 provides a received signal to a respective receiver unit (RCVR) 222. Each receiver unit 222 performs processing complementary to that performed by transmitter unit 254 and provides a received symbol stream. An RX spatial processor 240 performs receiver spatial processing on the N _ap received symbol streams from N _ap receiver units 222 and provides N _up recovered uplink data symbol streams. Receiver spatial processing is performed according to Channel Correlation Matrix Inversion (CCMI), minimum Mean Square Error (MMSE), soft Interference Cancellation (SIC), or some other technique. Each recovered uplink data symbol stream is an estimate of the data symbol stream transmitted by the respective corresponding user terminal. An RX data processor 242 processes (e.g., demodulates, deinterleaves, and decodes) each recovered uplink data symbol stream based on the rate for that stream to obtain decoded data. The decoded data for each user terminal may be provided to a data sink 244 for storage and/or to the controller 230 for further processing. The controller 230 may be coupled with a memory 232.

On the downlink, at access point 110, a TX data processor 210 receives traffic data from a data source 208 for N _dn user terminals scheduled for downlink transmission, control data from a controller 230, and possibly other data from a scheduler 234. Various types of data may be transmitted on different transport channels. TX data processor 210 processes (e.g., encodes, interleaves, and modulates) the traffic data for each user terminal based on the rate selected for that user terminal. TX data processor 210 provides N _dn downlink data symbol streams for N _dn user terminals. TX spatial processor 220 performs spatial processing (such as precoding or beamforming, as described in this disclosure) on the N _dn downlink data symbol streams and provides N _ap transmit symbol streams for the N _ap antennas. Each transmitter unit 222 receives and processes a respective corresponding transmit symbol stream to generate a downlink signal. N _ap transmitter units 222 provide N _ap downlink signals for transmission from N _ap antennas 224 to the user terminal.

At each user terminal 120, N _ut,m antennas 252 receive the N _ap downlink signals from access point 110. Each receiver unit 254 processes a received signal from an associated antenna 252 and provides a stream of received symbols. An RX spatial processor 260 performs receiver spatial processing on the N _ut,m received symbol streams from N _ut,m receiver units 254 and provides a recovered downlink data symbol stream for the user terminal. Receiver spatial processing is performed in accordance with CCMI, MMSE, or some other technique. An RX data processor 270 processes (e.g., demodulates, deinterleaves, and decodes) the recovered downlink data symbol stream to obtain decoded data for the user terminal. The decoded data for each user terminal may be provided to a data sink 272 for storage and/or to a controller 280 for further processing.

At each user terminal 120, a channel estimator 278 estimates the downlink channel response and provides a downlink channel estimate, which may include channel gain estimates, SNR estimates, noise variance, and the like. Similarly, at access point 110, channel estimator 228 estimates the uplink channel response and provides an uplink channel estimate. The controller 280 of each user terminal typically derives the spatial filter matrix for that user terminal based on the downlink channel response matrix H _dn,m for that user terminal. The controller 230 derives a spatial filter matrix for the access point based on the effective uplink channel response matrix H _up,eff. The controller 280 of each user terminal may send feedback information (e.g., downlink and/or uplink eigenvectors, eigenvalues, SNR estimates, etc.) to the access point. Controllers 230 and 280 also control the operation of various processing units at access point 110 and user terminal 120, respectively.

In Wi-Fi networks, wireless devices, such as APs and STAs, may perform Clear Channel Assessment (CCA) to determine whether a transmission channel is busy or idle in order to determine whether data may be transmitted to another wireless device. CCA has two components: carrier Sense (CS) and energy detection. Carrier sensing refers to the ability of a wireless device (e.g., an AP or STA) to detect and decode an incoming Wi-Fi preamble with information that enables the receiver to acquire wireless signals from and synchronize with transmitters from other wireless devices. For example, the first AP may broadcast a Wi-Fi signal preamble, and the Wi-Fi signal preamble may be detected by the second AP or STA. Similarly, the third AP may broadcast a Wi-Fi signal preamble, and the Wi-Fi signal preamble may be detected by the second AP. When the second AP detects one or more of the Wi-Fi signal preambles, the second AP may determine that the transmission channel is busy and may not transmit data. CCA may remain busy for the length of the transmission frame associated with the Wi-Fi preamble.

The second component of CCA is energy detection, which refers to the ability of a wireless device to detect the level of energy present on a transmission channel. The energy level may be based on different interference sources, wi-Fi transmissions, noise floor, and/or environmental energy. Wi-Fi transmissions may include unidentifiable Wi-Fi transmissions that have been corrupted or are too weak to be able to decode the transmission any more. Unlike carrier sensing, where the exact length of time that the transmission channel is busy can be known, energy detection uses periodic sampling of the transmission channel to determine whether energy is present. Additionally, energy detection may require at least one threshold that is used to determine whether the reported energy level is sufficient to report the transmission channel as busy or idle. This energy level may be referred to as the ED level/ED threshold level or CCA sensitivity level. For example, if the ED level is above a threshold, the wireless device may defer to other devices by refraining from transmitting.

In one aspect of communicating over a medium, a device may reduce transmit power, which may result in loss of coverage or throughput. Another possibility is to increase the CCA threshold (e.g. the energy detection level threshold), but doing so may create coexistence issues. As such, there is a need to achieve media coexistence without unduly reducing throughput or creating coexistence issues.

Fig. 3 illustrates an exemplary method 300 for communicating over a medium. Referring to fig. 3, a first AP302 and a first STA 306 may be associated with a first BSS (BSS 1). The second AP 304 and the second STA308 may be associated with a second BSS (BSS 2). The first AP302 may be within CCA range of the second AP 304. In various aspects, the first AP302 and/or the second AP 304 may monitor the shared transmission medium to determine one or more parameters. In an aspect, the second AP 304 may send the first transmission 312 to the second STA308 on a channel. In an aspect, the second STA308 may measure a Received Signal Strength Indicator (RSSI) of the first transmission 312 and provide the RSSI measurement to the second AP 304 in the first feedback message 314.

Referring to fig. 3, a first transmission 312 from a second AP 304 may cause interference to a first AP 302 associated with a first BSS. In one configuration, upon detecting the first transmission 312 (e.g., detecting a preamble or energy detection level above a threshold), the first AP 302 may refrain from transmitting due to the medium being busy. In one configuration, the first AP 302 may detect interference based on detecting the first transmission 312, such as by detecting energy associated with the first transmission 312.

In an aspect, in the first mode, the first AP 302 may transmit several data frames, with each transmission separated by a fixed time interval. In this first mode, each data frame may be transmitted concurrently with another data frame transmitted by the second AP 304. In the second mode, one or more of the APs 302, 304 may transmit data frames at different times. For example, the first AP 302 may transmit the data frame at the end of a random time interval that follows the fixed time interval. The second AP 304 may transmit the data frame at the end of a different random time interval that follows the fixed time interval.

In an aspect, although fig. 3 depicts network entity 310 as a separate entity within a network that manages the medium, network entity 310 may also be a component within first AP 302 and/or second AP 304. The network entity 310 may communicate (e.g., over a communication link 318) with the first AP 302 and/or the second AP 304.

Fig. 4A and 4B illustrate diagrams 400, 450 of an AP operating in a first mode and a second mode. Referring to fig. 4A, both the first AP 302 and the second AP 304 may have data for transmission. After an inter-frame space (IFS), such as a Point Coordination Function (PCF) inter-frame space (PIFS) or a Distributed Coordination Function (DCF) inter-frame space (DIFS), the first and second APs 302, 304 may perform CCA. Based on the CCA, the second AP 304 may determine that the medium is available and may transmit the packet B1 (e.g., the first transmission 312) after performing the CCA. The first AP 302 may also perform CCA and detect a packet transmission (packet B1). In one configuration, the first AP 302 may determine that the medium or channel is busy and may not transmit. In another configuration, based on the first channel information message 316 and/or the third channel information message 322, the network entity 310 may instruct (via the first control message 326) the first AP 302 to operate in the first mode and may instruct (e.g., via the second control message 328) the second AP 304 to operate in the first mode to increase the use of the medium. In the first mode, the first AP 302 may wait for the transmission of the packet B1 to complete. After a fixed interval (e.g., IFS) during which the first and second APs 302, 304 detect a lack of traffic (e.g., detect no traffic after packet B1 is transmitted), the first AP 302 may concurrently transmit packet A1 (e.g., second transmission 320) while the second AP 304 transmits packet B2. After another fixed interval (e.g., PIFS or DIFS), the first AP 302 may transmit packet A2 concurrently with the transmission of packet B3 by the second AP 304. After another fixed interval, the first AP 302 may transmit packet A3 concurrently with the transmission of packet B4 by the second AP 304. And finally, the first AP 302 may transmit the packet A4 concurrently with the transmission of the packet B5 by the second AP 304. In an aspect, the AP may perform CCA during each fixed interval.

In another aspect, one or more of the APs 302, 304 may follow a backoff procedure (e.g., a standard backoff procedure may be defined in one or more 802.11 specifications). Such back-off procedure may use some Arbitration IFS (AIFS) and/or SLOT time parameter for back-off countdown. According to CCA, if the medium is idle for an AIFS time, one or more of the APs 302, 304 may decrement the back-off counter by 1, and one or more of the APs 302, 304 may then further decrement the back-off counter by 1 for each successive SLOT time during which the medium remains continuously idle. In an aspect, AIFS may be equal to Short IFS (SIFS) + (1 SLOT) =pifs; but AIFS may be larger.

Once the medium is accessed, the second AP 304 may transmit a sequence (e.g., PPDU B1, B2, …, BN) containing at least one Physical Layer Convergence Procedure (PLCP) protocol data unit (PPDU). Each PPDU of the sequence may be separated by the same AIFS time. In some aspects, AIFS is equal to PIFS (e.g., based on certain conditions).

The first AP 302 may detect at least one of the PPDUs (e.g., B1), and the first AP 302 may stop the backoff of the first AP 302, thereby deferring the transmission of the first AP 302. Once at least one PPDU (e.g., B1) ends, the first AP 302 may sense the medium for an AIFS time, and the first AP 302 may decrement the backoff counter by 1. If the backoff counter reaches 0, the first AP 302 may transmit a packet A1 (e.g., of a sequence containing at least one PPDU). In some aspects, the first AP 302 may transmit the packet A1 in the at least one PPDU contemporaneously (e.g., simultaneously) with the packet B2. Once packet A1 is complete, the first AP 302 may perform channel sensing for PIFS time and if the channel is idle, the first AP 302 may transmit packet A2. Similarly, once B2 is complete, the second AP 304 may perform channel sensing for PIFS time and if the channel is idle, the second AP 304 may transmit packet B3. In some aspects, the first and/or second APs 302, 304 may refrain from additional SLOT time sensing, e.g., until a duration of a transmission sequence (e.g., of a PPDU) exceeds a transmit opportunity (TXOP) value.

The first and second APs 302, 304 may concurrently transmit a sequence of packets when the APs are in the first mode. That is, packets transmitted by the first AP 302 may be time synchronized with packets transmitted by the second AP 304. In an aspect, the packets may have the same length and may have a relatively short length. In another aspect, packets from the first AP 302 and the second AP 304 may have different lengths, but less than a threshold length. In another aspect, the packet length may be signaled by the network entity 310. As shown in fig. 4A, the start of each packet transmission may be at about the same time, regardless of the packet length. In another aspect, each AP may first transmit a Clear To Send (CTS) packet indicating that each AP intends to use the shared medium for data transmission before transmitting the sequence of packets. The CTS packet may include a special address or indication that indicates that other APs are not to back off. In another aspect, each AP may end the sequence of packets with a CTS until the end of the maximum time interval.

As such, in the first mode, the AP may transmit a sequence of relatively short data frames that are all separated by an IFS (e.g., PIFS). In an aspect, the IFS or fixed interval may be specified by the network entity 310 and communicated to the first and second APs 302, 304. After entering the first mode, the first AP 302 that was initially back-off in the second mode will wait until the end of the packet (e.g., packet B1) and then collide on all subsequent frames. As noted, synchronization may be maintained even if the packet sizes are not the same length, as one AP may wait for another AP. In the packet transmission sequence in the first mode, the contention window of each AP may be set to 0 or some other common value between APs. For example, the fixed time interval may be a DIFS or PIFS, and the AP may transmit after a contention window in which the value is set to 0. In another aspect, instead of DIFS or PIFS, the AP may delay transmission up to SIFS.

In an aspect, the first and second APs 302, 304 may remain in the first mode and transmit a number of relatively short packets (or data frames) within a maximum time interval (e.g., 200 ms). Subsequently, after a maximum time interval, the first and second APs 302, 304 may terminate the transmission. In an aspect, the first and second APs 302, 304 may autonomously revert to the second mode without receiving further signaling from the network entity 310. In another aspect, the first and second APs 302, 304 may remain in the first mode until otherwise indicated by the network entity 310.

Fig. 4B illustrates a diagram 450 in which the first and second APs 302, 304 operate in a second mode. In this mode, the first and second APs 302, 304 do not transmit overlapping each other. In this mode, both APs may perform CCA after IFS after transmission. The second AP 304 may perform a CCA and determine that the medium is available and transmit packet B1. The first AP 302 may perform a CCA and detect packet B1 and determine that the medium is busy. After packet B1 is transmitted and after the IFS has passed, the first AP 302 may wait for a random back-off time (shown as random back-off 1 (Random Backoff 1) in fig. 4B) and perform CCA again. The first AP 302 may transmit packet A1 if the medium is available. Subsequently, after an IFS has passed after packet A1 is transmitted, the second AP 304 may wait for a random back-off time (shown in fig. 4B as random back-off 2 (Random Backoff 2) and then perform a cca-if the medium is available, the second AP 304 may transmit packet B2-unlike fig. 4A, the transmission times of the first and second APs 302, 304 are not aligned and each AP will back off while the other AP is transmitting.

Fig. 5A and 5B illustrate diagrams 500, 550 relating to sequence robustness. Even assuming good time synchronization, one AP (e.g., the first AP 302) may start its scheduled transmission sequence with a delay. In a first option, as shown in fig. 5A, each AP may wait for an IFS (e.g., DIFS) and perform a CCA. However, the first AP302 may start its transmission sequence with a delay. If the transmission would exceed the maximum time interval, the network entity 310 may instruct the first AP302 to stop transmitting. For example, the first AP302 may stop transmitting after packet A3 and not transmit packet A4. The second option may be preferred and may also facilitate the block acknowledgement procedure.

Fig. 6A and 6B illustrate diagrams 600, 650 of acknowledging a transmission in a synchronization sequence. For example, referring to fig. 6A, assuming the second option is utilized, the first and second APs 302, 304 may schedule a Block Acknowledgement Request (BAR) and a Block Acknowledgement (BA). In an aspect, the BAR may be scheduled after a maximum time interval. In another aspect, the AP may initiate transmission of the BAR when a traffic loss is detected after the data transmission. In an aspect, the BAR and BA may be hard scheduled. That is, the BAR and BA may be transmitted after the medium is deemed idle beyond the PIFS.

Referring to fig. 6B, if a subsequent AP (or first AP 302) is allowed to transmit, the BAR and BA cannot be hard scheduled. In this regard, the AP may use deterministic backoff with AIFS. The deterministic backoff may have a large AIFS to provide time for subsequent APs to complete transmitting subsequent packets. In an aspect, the sequence in fig. 6B may be implemented using concatenation, even though the AP is within transmission range.

In an aspect, for fig. 6A and 6B, the network entity 310 may signal the first and second APs 302, 304 to set the acknowledgement policy to BAR for all frames. As such, for example, frames may not be acknowledged unless a BAR is included with the frame or transmitted separately after the frame. In another aspect, the AP may transmit the BAR to the STA during the assigned slot time.

Fig. 7 is a diagram 700 illustrating an exemplary method for communicating over a medium. Referring to fig. 7, in an aspect, communications may occur on a medium when APs are loosely synchronized and within CCA range. In fig. 7, the AP may be instructed to collide deterministically by using IFS (e.g., PIFS) bursts. Referring to fig. 7, the downlink controlled access zone may include a data zone for data transmission and a BA zone for BAR and BA transmission. During the data interval, and after the IFS, the AP may transmit a CTS frame. Through IFS after transmitting the CTS frame, the AP may transmit a sequence of packets to its associated STA. Each packet in the sequence of packets may be separated by a fixed time interval (e.g., PIFS). In another aspect, as shown in the previous figures, the AP may transmit the entire sequence of packets during the data interval before transmitting the BAR or BA during the BA interval. After transmitting the sequence of packets, the AP may transmit another CTS frame.

Fig. 8 illustrates an example functional block diagram of a wireless device 802 configured to communicate over a medium. Wireless device 802 is an example of a device that may be configured to implement the various methods described herein. For example, wireless device 802 can be AP 110 and/or UT 120.

The wireless device 802 may include a processor 804 that controls the operation of the wireless device 802. The processor 804 may also be referred to as a Central Processing Unit (CPU). Memory 806, which may include both Read Only Memory (ROM) and Random Access Memory (RAM), may provide instructions and data to the processor 804. A portion of the memory 806 may also include non-volatile random access memory (NVRAM). The processor 804 typically performs logical and arithmetic operations based on program instructions stored within the memory 806. The instructions in the memory 806 may be executable (e.g., by the processor 804) to implement the methods described herein.

The wireless device 802 may also include a housing 808, and the wireless device 802 may include a transmitter 810 and a receiver 812 to allow data transmission and reception between the wireless device 802 and a remote device. The transmitter 810 and the receiver 812 may be combined into a transceiver 814. A single transmit antenna or multiple transmit antennas 816 may be attached to the housing 808 and electrically coupled to the transceiver 814. The wireless device 802 may also include multiple transmitters, multiple receivers, and multiple transceivers.

The wireless device 802 may also include a signal detector 818 that may be used to attempt to detect and quantify the level of signals received by the transceiver 814 or the receiver 812. Signal detector 818 may detect signals such as total energy, energy per subcarrier per symbol, power spectral density, and other signals. The wireless device 802 may also include a Digital Signal Processor (DSP) 820 for use in processing signals. DSP 820 may be configured to generate a packet for transmission. In some aspects, the packet may include a PPDU.

The various components of the wireless device 802 may be coupled together by a bus system 822, which bus system 822 may include a power bus, a control signal bus, and a status signal bus in addition to a data bus. The wireless device 802 may include a media component 824. The media component 824, which may include one or more interfaces, such as a bus interface (e.g., of a processor), may be configured to perform various operations. The media component 824 may be configured as a first interface configured to obtain signals from a wireless node. The media component 824 may be configured to: selecting to operate in either the first mode or the second mode in response to the signal; detecting a traffic loss on the shared medium during a fixed time interval; and initiate a data transmission at the end of the fixed time interval if operating in the first mode; or initiate a data transmission at the end of a random time interval following a fixed time interval if operating in the second mode. The media component 824 may be further configured to initiate data transmission in the first mode by generating a plurality of data frames separated by a fixed time interval, and to output the plurality of data frames for transmission. The media component 824 may be further configured to terminate the data transmission if a time period associated with the data transmission exceeds a maximum time interval, the time period following initiation of the data transmission. The media component 824 may be further configured to generate a block acknowledgement request and schedule transmission of the block acknowledgement request after a maximum time interval and output the block acknowledgement request for the scheduled transmission. The media component 824 may be further configured to initiate transmission of a block acknowledgement if another traffic loss is detected on the shared medium after the end of the data transmission. The media component 824 may be further configured to monitor the shared media to determine one or more parameters and provide the one or more parameters to the remote wireless node. In an aspect, the one or more parameters include at least one of a received signal strength from a wireless node in communication with the equipment or a detected interference associated with the shared medium.

Fig. 9 is a flow chart 900 of a method for communicating over a medium. The first method may be performed using equipment (e.g., AP 110, UT 120, wireless device 802, or media component 824). Although the method is described below with respect to elements of wireless device 802 of fig. 8, other components may be used to implement one or more of the steps described herein.

At operation 902, the apparatus may be configured to monitor a shared transmission medium to determine one or more parameters and provide the one or more parameters to a remote apparatus. The apparatus may monitor the shared transmission medium by determining whether a signal is transmitted on the shared transmission medium and by receiving the signal on the shared transmission medium. The apparatus may determine the one or more parameters by measuring the RSSI of the received signal or by measuring the energy detection level (e.g., interference) on the transmission medium and by storing the measurements. In another aspect, the apparatus may determine the one or more parameters by receiving the one or more parameters, such as by receiving RSSI from another wireless node (e.g., STA). For example, the first AP 302 and/or the second AP304 may monitor the shared transmission medium to determine one or more parameters, and the first AP 302 and/or the second AP304 may provide the determined one or more parameters to the network entity 310.

At operation 904, the apparatus may obtain a signal from a remote wireless node. For example, the signal may include instructions configured to cause the apparatus to select between different transmission modes. In an aspect, the remote wireless node may be a network server. In the context of fig. 3, the first AP 302 may receive a control message 326 from the network entity 310 and/or the second AP 304 may receive a control message 328 from the network entity 310.

At 906, the apparatus may select to operate in a first mode or a second mode in response to the signal; for example, the apparatus may switch between the first modes by setting the mode status indicator to a first value or a second value corresponding to the selected mode. For example, the first AP 302 may select to operate in the first mode or the second mode in response to the control message 326 and/or the second AP 304 may select to operate in the first mode or the second mode in response to the control message 328.

At operation 908, the apparatus may detect a lack of traffic on the shared transmission medium during a fixed time interval. For example, the apparatus may sense the shared transmission medium by determining whether any signals (e.g., signals above a signal strength) are present in the medium and if not determining whether signals are absent or below the signal strength for more than a duration of time. For example, the first AP 302 and/or the second AP 304 may detect a lack of traffic on the shared transmission medium.

At operation 910, the apparatus may initiate a data transmission at the end of a fixed time interval if operating in the first mode or at the end of a random time interval after the fixed time interval if operating in the second mode. For example, the apparatus may start a timer having a duration of a fixed time interval. Upon expiration of the timer, the apparatus may initiate a data transmission if operating in the first mode. If operating in the second mode, the apparatus may additionally wait for a randomly selected time interval to elapse and then initiate a data transmission. For example, the first AP302 and/or the second AP 304 may initiate data transmission at the end of the fixed time interval if operating in the first mode. In the first mode, one or more data frames transmitted by the first AP302 may be synchronized (e.g., concurrent) with one or more data frames transmitted by the second AP 304. In the second mode, the first AP302 or the second AP 304 may initiate data transmission at the end of a random time interval that follows a fixed time interval.

In an aspect, the apparatus may perform operation 912 and/or operation 914 to initiate a data transmission at the end of a fixed time interval if operating in the first mode or at the end of a random time interval after the fixed time interval if operating in the second mode. At operation 912, the apparatus may generate a plurality of data frames separated by a fixed time interval. For example, the first AP 302 may generate one or more of the packets A1-A4 and/or the second AP 304 may generate one or more of the packets B2-B5.

At operation 914, the apparatus may output a plurality of data frames for transmission. For example, the first AP 302 may output one or more of the packets A1-A4 and/or the second AP 304 may output one or more of the packets B2-B5.

At operation 916, the apparatus may terminate the data transmission if the time period associated with the data transmission exceeds the maximum time interval. For example, the first AP 302 may terminate the data transmission if the time period associated with the data transmission exceeds the maximum time interval, and/or the second AP 304 may terminate the data transmission if the time period associated with the data transmission exceeds the maximum time interval.

At operation 918, the apparatus may generate a block acknowledgement request. For example, the first AP 302 may generate a block acknowledgement request and/or the second AP 304 may generate a block acknowledgement request.

At operation 920, the apparatus may schedule transmission of a block acknowledgement request after a maximum time interval. For example, the apparatus may detect the shared transmission medium as idle, and the apparatus may hard schedule a block acknowledgement request after a maximum time interval. For example, the first AP 302 may schedule a block acknowledgement request after a maximum time interval and/or the second AP 304 may schedule a block acknowledgement request after a maximum time interval.

At operation 922, the apparatus may output a block acknowledgement request for the scheduled transmission. For example, when a traffic loss is detected after a data transmission, the apparatus may initiate transmission of a block acknowledgement according to the scheduled transmission. For example, the first AP 302 may output a block acknowledgement request for a scheduled transmission and/or the second AP 304 may output a block acknowledgement request for a scheduled transmission.

At operation 924, the apparatus may initiate transmission of a block acknowledgement if another traffic loss is detected on the shared medium after the end of the data transmission. For example, the apparatus may detect another traffic loss on the shared medium and may initiate transmission of a block acknowledgement based on the detection of the other traffic loss. For example, the first AP 302 and/or the second AP 304 may initiate transmission of a block acknowledgement if another traffic loss is detected on the shared medium after the end of the data transmission.

Fig. 10 illustrates an exemplary device 1000 capable of performing the operations set forth in fig. 9. The example apparatus may include means 1002 for monitoring a shared transmission medium to determine one or more parameters and providing the one or more parameters to a remote device. Apparatus 1002 may include a bus interface, antenna 224, antenna 252, receiver unit 222, receiver unit 254, RX spatial processor 240, RX spatial processor 260, RX data processor 242, RX data processor 270, transmitter unit 222, transmitter unit 254, TX spatial processor 220, TX spatial processor 290, TX data processor 210, TX data processor 288, controller 230, controller 280, antenna 816, transmitter 810, receiver 812, digital signal processor 820, and/or processor 804 (e.g., of the processors) as illustrated in fig. 2 and 8.

The example apparatus may include means 1004 for acquiring a signal from a remote wireless node. Device 1004 may include bus interface (e.g., of the processor) shown in fig. 2 and 8, antenna 224, antenna 252, receiver unit 222, receiver unit 254, RX spatial processor 240, RX spatial processor 260, RX data processor 242, RX data processor 270, controller 230, controller 280, antenna 816, receiver 812, digital signal processor 820, and/or processor 804.

The example apparatus may include means 1006 for selecting operation in the first mode or the second mode in response to the signal. The means 1006 may include the controller 230, the controller 280, the digital signal processor 820, and/or the processor 804 shown in fig. 2 and 8.

The example apparatus may include means 1008 for detecting a lack of traffic on the shared medium during a fixed time interval. Device 1008 may include bus interface (e.g., of the processor) shown in fig. 2 and 8, antenna 224, antenna 252, receiver unit 222, receiver unit 254, RX spatial processor 240, RX spatial processor 260, RX data processor 242, RX data processor 270, controller 230, controller 280, antenna 816, receiver 812, digital signal processor 820, and/or processor 804.

An example apparatus may include means for initiating a data transmission at the end of a fixed time interval if operating in a first mode; or means 1010 for initiating a data transmission at the end of a random time interval following the fixed time interval if operating in the second mode. In an aspect, the apparatus 1010 may be configured to generate a plurality of data frames separated by a fixed time interval. In an aspect, the apparatus 1010 may be configured to output a plurality of data frames for transmission. The apparatus 1010 may include the bus interface (e.g., of the processor) shown in fig. 2 and 8, the antenna 224, the antenna 252, the transmitter unit 222, the transmitter unit 254, the TX spatial processor 220, the TX spatial processor 290, the TX data processor 210, the TX data processor 288, the controller 230, the controller 280, the antenna 816, the transmitter 810, the digital signal processor 820, and/or the processor 804.

The example apparatus may include means 1012 for terminating the data transmission if a time period associated with the data transmission exceeds a maximum time interval. The apparatus 1012 may include the controller 230, the controller 280, the digital signal processor 820, and/or the processor 804 shown in fig. 2 and 8.

The example apparatus may include means 1014 for generating a block acknowledgement request. The apparatus 1014 may include the controller 230, the controller 280, the digital signal processor 820, and/or the processor 804 shown in fig. 2 and 8.

The example apparatus may include means 1016 for scheduling transmission of the block acknowledgement request after a maximum time interval. The device 1016 may include the controller 230, the controller 280, the digital signal processor 820, and/or the processor 804 shown in fig. 2 and 8.

The example apparatus may include means 1018 for outputting a block acknowledgement request for the scheduled transmission. Device 1018 may include the bus interface (e.g., of the processor) shown in fig. 2 and 8, antenna 224, antenna 252, transmitter unit 222, transmitter unit 254, TX spatial processor 220, TX spatial processor 290, TX data processor 210, TX data processor 288, controller 230, controller 280, antenna 816, transmitter 810, digital signal processor 820, and/or processor 804.

The example apparatus may include means 1020 for initiating transmission of a block acknowledgement if another traffic loss is detected on the shared medium after the end of the data transmission. Apparatus 1020 may include a bus interface (e.g., of the processor) illustrated in fig. 2 and 8, antenna 224, antenna 252, transmitter unit 222, transmitter unit 254, TX spatial processor 220, TX spatial processor 290, TX data processor 210, TX data processor 288, controller 230, controller 280, antenna 816, transmitter 810, digital signal processor 820, and/or processor 804.

In the example apparatus 1000, one or more of the apparatuses may be at least partially the same apparatus. For example, apparatus 1004 may include a first interface to obtain a signal and apparatus 1010 may include a second interface to output a plurality of data frames. Potentially, the first interface and the second interface may be the same interface.

The various operations of the methods described above may be performed by any suitable device capable of performing the operations. These means may comprise various hardware and/or software components and/or modules including, but not limited to, circuits, application Specific Integrated Circuits (ASICs), or processors. In general, any operations illustrated in the figures may be performed by corresponding functional devices capable of performing the operations.

As used herein, the term "determining" encompasses a wide variety of actions. For example, "determining" may include calculating, computing, processing, deriving, researching, looking up (e.g., looking up in a table, database, or another data structure), ascertaining, and the like. Also, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in memory), and the like. "determining" may also include parsing, selecting, choosing, establishing, and the like.

As used herein, the term receiver may refer to an RF receiver (e.g., an RF receiver of an RF front-end) or an interface (e.g., an interface of a processor) for receiving structures processed by the RF front-end (e.g., via a bus). Similarly, the term transmitter may refer to an RF transmitter of an RF front end or an interface (e.g., an interface of a processor) for outputting a structure (e.g., via a bus) to the RF front end for transmission.

As used herein, a phrase referring to a list of items "at least one of" refers to any combination of these items, including individual members. As an example, "at least one of a, b, or c" is intended to encompass: a. b, c, a-b, a-c, b-c, and a-a, b-b, and c-c.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a field programmable gate array signal (FPGA) or other Programmable Logic Device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of a method or algorithm described in connection with the disclosure may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software modules may reside in any form of storage medium known in the art. Some examples of storage media that may be used include Random Access Memory (RAM), read Only Memory (ROM), flash memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, and so forth. A software module may comprise a single instruction, or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media. A storage medium may be coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor.

The methods disclosed herein comprise one or more steps or actions for achieving the described method. These method steps and/or actions may be interchanged with one another without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.

The described functions may be implemented in hardware, software, firmware, or any combination thereof. If implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system may be implemented with a bus architecture. The bus may include any number of interconnecting buses and bridges depending on the specific application of the processing system and the overall design constraints. The bus may link together various circuits including processors, machine-readable media, and bus interfaces. A bus interface may be used to connect network adapters and the like to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the case of the user terminal 120 (see fig. 1), a user interface (e.g., keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further.

The processor may be responsible for managing the bus and general processing, including the execution of software stored on a machine-readable medium. A processor may be implemented with one or more general-purpose and/or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuitry capable of executing software. Software should be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. By way of example, a machine-readable medium may comprise RAM (random access memory), flash memory, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read only memory), registers, a magnetic disk, an optical disk, a hard drive, or any other suitable storage medium, or any combination thereof. The machine-readable medium may be implemented in a computer program product. The computer program product may comprise packaging material.

In a hardware implementation, the machine-readable medium may be part of a processing system that is separate from the processor. However, as will be readily appreciated by those skilled in the art, the machine-readable medium, or any portion thereof, may be external to the processing system. By way of example, machine-readable media may comprise a transmission line, a carrier wave modulated by data, and/or a computer product separate from the wireless node, all of which may be accessed by the processor through a bus interface. Alternatively or additionally, the machine-readable medium, or any portion thereof, may be integrated into the processor, such as the cache and/or general purpose register file, as may be the case.

The processing system may be configured as a general-purpose processing system having one or more microprocessors that provide processor functionality, and external memory that provides at least a portion of a machine-readable medium, all linked with other supporting circuitry by an external bus architecture. Alternatively, the processing system may be implemented with an ASIC (application specific integrated circuit) with a processor, a bus interface, a user interface (in the case of an access terminal), supporting circuitry, and at least a portion of a machine-readable medium, integrated in a single chip, or with one or more FPGAs (field programmable gate arrays), PLDs (programmable logic devices), controllers, state machines, gating logic, discrete hardware components, or any other suitable circuitry, or any combination of circuits capable of executing the various functionalities described throughout this disclosure. Those skilled in the art will recognize how best to implement the functionality described with respect to the processing system, depending on the particular application and the overall design constraints imposed on the overall system.

The machine-readable medium may include several software modules. The software modules include instructions that, when executed by a processor, cause the processing system to perform various functions. These software modules may include a transmit module and a receive module. Each software module may reside in a single storage device or be distributed across multiple storage devices. As an example, when a trigger event occurs, the software module may be loaded into RAM from a hard drive. During execution of the software module, the processor may load some instructions into the cache to increase access speed. One or more cache lines may then be loaded into a general purpose register file for execution by the processor. Where functionality of a software module is described below, it will be understood that such functionality is implemented by a processor when executing instructions from the software module.

If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a web site, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital Subscriber Line (DSL), or wireless technologies such as Infrared (IR), radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk (disc) and disc (disc), as used herein, includes Compact Disc (CD), laser disc, optical disc, digital Versatile Disc (DVD), floppy disk, and diskA disc, in which the disc (disk) often magnetically reproduces data, and the disc (disk) optically reproduces data with a laser. Thus, in some aspects, a computer-readable medium may comprise a non-transitory computer-readable medium (e.g., a tangible medium). Additionally, for other aspects, the computer-readable medium may include a transitory computer-readable medium (e.g., a signal). Combinations of the above should also be included within the scope of computer-readable media.

Thus, certain aspects may include a computer program product for performing the operations presented herein. For example, such computer program products may include a computer-readable medium having instructions stored (and/or encoded) thereon that are executable by one or more processors to perform the operations described herein. For certain aspects, the computer program product may comprise packaging material.

Further, it should be appreciated that modules and/or other suitable means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by a user terminal and/or base station as applicable. For example, such a device can be coupled to a server to facilitate transfer of an apparatus for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage device (e.g., RAM, ROM, a physical storage medium such as a Compact Disc (CD) or floppy disk, etc.), such that the apparatus can obtain the various methods once the storage device is coupled to or provided to a user terminal and/or base station. Further, any other suitable technique suitable for providing the methods and techniques described herein to a device may be utilized.

It is to be understood that the claims are not limited to the precise configurations and components illustrated above. Various modifications, substitutions and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A method of wireless communication by a first device, comprising:

Receiving a first message associated with a synchronous transmission over a wireless channel; and

Initiating transmission of a first sequence of packets based on a schedule for the synchronized transmission with at least one second apparatus on the wireless channel, wherein the schedule is based on the first message, wherein a first start time of the first sequence of packets and a second start time of at least one second sequence of packets transmitted by the at least one second apparatus are synchronized on the wireless channel, and wherein a first packet of the first sequence of packets is separated in time from a second packet of the first sequence of packets based on a first coordinated inter-frame space, IFS, period for the first apparatus and the at least one second apparatus.

2. The method of claim 1, wherein a first length of at least one packet in the first sequence of packets is different from a second length of at least one packet in the at least one second sequence of packets.

3. The method of claim 2, wherein each of the first length and the second length is less than a packet length threshold.

4. The method of claim 1, wherein a first end time of at least one packet in the first sequence of packets is not synchronized with a second end time of at least one packet in the at least one second sequence of packets over the wireless channel.

5. The method of claim 1, further comprising:

detecting a lack of traffic on the wireless channel,

Wherein transmission of the first sequence of packets is initiated further based on the traffic loss.

6. The method of claim 5, further comprising:

A clear channel assessment CCA procedure is performed on the wireless channel,

Wherein the absence of traffic on the wireless channel is detected based on the CCA procedure.

7. The method of claim 5, wherein the lack of traffic on the wireless channel is detected during a second coordinated inter-frame space IFS period.

8. The method of claim 1, further comprising:

determining that the wireless channel is busy; and

Deferring transmission of the first sequence of packets based on the wireless channel being busy,

Wherein transmission of the first sequence of packets is initiated after deferring transmission of the first sequence of packets.

9. The method of claim 8, further comprising:

detecting energy on the wireless channel; and

The energy is compared to a threshold value,

Wherein the wireless channel is determined to be busy based on the energy being compared to the threshold.

10. A first apparatus for wireless communication, comprising:

Means for receiving a first message associated with a synchronous transmission over a wireless channel; and

Means for initiating transmission of a first sequence of packets based on a schedule for the synchronized transmission with at least one second apparatus on the wireless channel, wherein the schedule is based on the first message, wherein a first start time of the first sequence of packets and a second start time of at least one second sequence of packets transmitted by the at least one second apparatus are synchronized on the wireless channel, and wherein a first packet of the first sequence of packets is separated in time from a second packet of the first sequence of packets based on a first coordinated inter-frame space, IFS, period for the first equipment and the at least one second apparatus.

11. The first apparatus of claim 10, wherein a first length of at least one packet in the first sequence of packets is different from a second length of at least one packet in the at least one second sequence of packets.

12. The first apparatus of claim 11, wherein each of the first length and the second length is less than a packet length threshold.

13. The first apparatus of claim 10, wherein a first end time of at least one packet in the first sequence of packets is unsynchronized with a second end time of at least one packet in the at least one second sequence of packets over the wireless channel.

14. The first apparatus of claim 10, further comprising:

Means for detecting a lack of traffic on the wireless channel,

15. The first apparatus of claim 14, further comprising:

Means for performing a clear channel assessment CCA procedure on the wireless channel,

16. The first apparatus of claim 14, wherein the lack of traffic on the wireless channel is detected during a second coordinated inter-frame space, IFS, period.

17. The first apparatus of claim 10, further comprising:

Means for determining that the wireless channel is busy; and

Means for deferring transmission of the first sequence of packets based on the wireless channel being busy,

18. The first apparatus of claim 17, further comprising:

means for detecting energy on the wireless channel; and

Means for comparing said energy to a threshold,

19. A first apparatus for wireless communication, comprising:

A memory; and

At least one processor coupled with the memory and configured to:

20. The first apparatus of claim 19, wherein a first length of at least one packet in the first sequence of packets is different from a second length of at least one packet in the at least one second sequence of packets.

21. The first device of claim 20, wherein each of the first length and the second length is less than a packet length threshold.

22. The first apparatus of claim 19, wherein a first end time of at least one packet in the first sequence of packets is unsynchronized with a second end time of at least one packet in the at least one second sequence of packets over the wireless channel.

23. The first apparatus of claim 19, wherein the at least one processor is further configured to:

detecting a lack of traffic on the wireless channel,

24. The first apparatus of claim 23, wherein the at least one processor is further configured to:

A clear channel assessment CCA procedure is performed on the wireless channel,

25. The first apparatus of claim 23, wherein the lack of traffic on the wireless channel is detected during a second coordinated inter-frame space, IFS, period.

26. The first apparatus of claim 19, wherein the at least one processor is further configured to:

determining that the wireless channel is busy; and

27. The first apparatus of claim 26, wherein the at least one processor is further configured to:

detecting energy on the wireless channel; and

The energy is compared to a threshold value,

28. A computer-readable medium storing computer executable code for wireless communication by a first device, the code when executed by a processor causing the processor to:

29. The computer readable medium of claim 28, wherein a first length of at least one packet in the first sequence of packets is different from a second length of at least one packet in the at least one second sequence of packets.

30. The computer-readable medium of claim 28, wherein a first end time of at least one packet in the first sequence of packets is unsynchronized with a second end time of at least one packet in the at least one second sequence of packets over the wireless channel.